Misaligned teeth are commonly realigned by applying a desired corrective force with a set of cooperating orthodontic appliances that are generally adapted to fit in the patient's mouth and to be worn for a period of time. Properly aligned teeth may also be stabilized with such orthodontic appliance systems. Much of the desired corrective or stabilizing force is applied with intra-oral appliances that are attached with connecting appliances to the buccal side of the tooth, that is, the side of the tooth adjacent to the cheek. However, some corrective force may be applied with auxiliary appliance systems that attach, directly or indirectly, to the patient's tooth on the lingual side, that is, the side of the tooth adjacent to the tongue.
Appliance systems for applying a desired force to a patient's teeth generally include a substantially rigid force-supplying appliance or member for supplying the desired force, and a plurality of connector appliances for rigidly attaching the force-supplying appliance to the particular teeth. Prior connectors comprised generally a connector sheath, tube, or channel adapted to be rigidly attached to a tooth and to receive and connect with a specially adapted portion of the force-supplying member. Generally, the connector sheaths or tubes were each attached to a band that fitted tightly around the tooth to be positioned; however, in some cases the sheaths or tubes were attached directly to the tooth by a suitable adhesive. Where no corrective force is applied by the force-supplying member, the connection between the force-supplying member and sheath or tube is said to be "passive," whereas, where corrective force is applied, the connection is said to be "active."
Common intra-oral auxiliary force-supplying appliances include palatal bars that extend transversely across the patient's palate for applying a desired force to the upper teeth, and lingual arches, which fit closely on the lingual side of the patient's teeth forming generally an arch shape to avoid interference with the patient's tongue.
Some prior orthodontic appliance systems used force-supplying members made of round wire. The ends of the members had a male connector, generally comprising a doubled wire section, that is, two side-by-side pieces of round wire. This doubled round wire connector end was adapted to fit tightly into a sheath having a generally rectangular, box-shaped receptacle. Connecting the force-supplying member to a particular tooth involved inserting the connector end of the force-supplying member into the sheath that had previously been attached to the particular tooth, and then tying the connector in place with a suitable ligature wire.
Other prior appliance systems had tubular sheaths, or tubes, for receiving a single round wire of the force-supplying appliance. With these round wire and tube connections, the force-supplying round wire member was usually required to have a control cross member, which could be tied to the tube for providing a desired rotational and torquing corrective force.
Some orthodontic appliance systems used a square wire force-supplying member that was adapted to be tied into a generally square channel connector that was attached to the tooth to be positioned or stabilized. This square-wire system provided some advantage in that the square wire and channel connection provided better rotational force control, and in many cases, much of the corrective force required to realign a tooth is rotational or torquing force.
There were a number of problems associated with the prior tooth-positioning systems. One such problem was that, where the force-applying member was a round wire, and the sheath receptacle generally rectangular, precise rotational force control was not possible because of the somewhat sloppy fit of the rounded wire in the rectangular receptacle, even when the round wire was doubled. The use of a control bar for helping control rotational force only partially compensated for the sloppy fit between the sheath and the force-supplying member.
Another problem was that each of the prior systems required that the force-supplying member be tied to the connector sheath or tube with a suitable ligature wire to provide a secure connection. The process of tying ligature wire was very time consuming and generally unpleasant for the patient. Furthermore, the sheaths often needed extra tying bars to facilitate tying.
With any of the prior rectangular sheath or square channel connector appliances, whether the force-supplying members were made of round wire or square wire, active connections were difficult because the connector end or portion of the force-supplying member had to be angled somewhat with respect to the sheath receptacle or channel prior to connection, in order to provide the desired force. That is, the fit between the force-supplying member connector end or connecting portion and the sheath or channel had to be as tight as possible to facilitate rotational control, yet the connector of the force-supplying member had to be angled prior to connection to apply the desired force. As a result, it was often very time consuming to make the desired active connection between the force-supplying member and the sheath or channel.
It is therefore an object of the invention to provide an orthodontic appliance system with a connector appliance that facilitates easy connection between the force-supplying member and the teeth to be positioned or stabilized.
Another object of the invention is to provide a connector appliance for orthodontic appliance systems that is easy to connect, yet provides good corrective force control, particularly, rotational force control.
Another object of the invention is to provide a connector appliance for orthodontic appliance systems, that locks into a connected position without the need for tying a ligature wire, and that may be easily released from the locked connected position.
These and other objects will be apparent from the following summary and description of the preferred embodiment, with reference to the drawings.